Prenatal exposure to alcohol results in a range of neurobehavioral problems including deficits in intellectual functioning, language development, attention, learning, memory, and motor skills. With regard to motor performance, we conducted a preliminary series of experiments that examined balance, reaction time, anticipation time, and movement speed control in children with prenatal exposure to alcohol. Results indicated that these individuals produced greater and more variable motor timing errors than non-exposed control children. Collectively, data from this work indicated that motor timing deficits occur at both the central (CNS) and peripheral (neuromuscular) levels of control, but the sources of these deficits remain unknown. Using a model driven approach, it is the purpose of the proposed research to systematically evaluate specific central and peripheral systems involved in motor timing behavior of children with prenatal-exposure to alcohol. Two experiments will assess if timing deficits in these children can be attributed to slower and more variable central processing in the response selection and response programming stages. Two additional projects will examine if timing deficits are related to delays in central clock processing and/or motor response delays. In addition to providing a better understanding of the mechanisms that contribute to timing deficits in the alcohol-exposed child, the information gathered can be used to create rehabilitation programs designed to specifically improve the daily functioning of these individuals, and facilitate interpretation of future studies examining the effects of age on motor skill performance.